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B2402, B2403, B2404

B2402 , B2403 , B2404

Air distribution flap stepping motor, shorting to ground, open circuit, shorting between connections



Conditions

B2402: Shorting to ground B2403: Generated only during calibration. Start fault diagnosis by reading the trouble codes, if any, and make a note of them. Then carry out calibration and read the trouble codes again. B2404: Shorting between connections.

Diagnostic procedure


1. Connect a BOB to the ACC control module's wiring (the control module should not be connected). Check the resistance of both windings in the stepping motors across terminals 23 and 24 and terminals 25 and 26. The correct resistance should be about 100 ohms in both cases.

Also check that no shorting to ground occurs by measuring the resistance across ground and terminals 23, 24, 25 and 26. The correct resistance is OL (infinite). Proceed directly to point 4 if all readings are OK.

2. If the resistance of the windings is not OK, measure the resistance again at connector H10-5 as follows:


• Across pins 5 and 6.

• Across pins 7 and 8.

In both cases the resistance should be about 100 ohms. If it is not, change the stepping motor.

3. Check the wiring between the ACC control module and connector H10-5 for shorting to ground or shorting between the terminals and/or open circuit. Locate the short circuit and rectify it.

4. Clear the diagnostic trouble codes, if any. Calibrate the ACC system. Check whether the diagnostic trouble code is generated afresh. If it is, proceed to section for further measures.